FOXBOROUGH - When a head-to-head collision last November in a game against the Colts left Patriot Mike Wright with a concussion that not only ended his season, but left him with dizziness, motion sickness, nausea, double vision, and ringing in his ears that lingered long after, the question was whether he would ever return to the field.

He did, but not for nearly as long as he had hoped. Another head-on hit - in this season’s opener against the Dolphins - left the defensive end with another concussion, and yesterday for the second straight year he was placed on injured reserve, bringing his season to a halt and again bringing into question his future in football.

“Mike did everything he could to return and contribute to the team,’’ said coach Bill Belichick of Wright, who attempted to practice last week in a limited capacity. “Unfortunately, we felt the best course of action was to place him on injured reserve at this time.’’

Wright, a seven-year veteran who was undrafted out of Cincinnati, had sustained concussions prior to the one in 2010, but the effects, he said at the time, didn’t linger.

Dr. Mark Lovell, founding director of the University of Pittsburgh Medical Center Sports Medicine Concussion Program, said there are two concerns when it comes to the possibility of a concussion threatening a player’s career.

“In general, what we look for is concussions that are happening closer together or with less provocation,’’ Lovell said. “When athletes start to tell you they’re being injured with less force, you start to talk about how it might be easier to have a concussion, and that’s a time when you start to worry about their safety.

“The one thing that people need to realize is it’s a very, very tricky injury. It manifests itself differently in different individuals and that’s what sometimes makes it difficult to diagnose and follow. There’s still a lot that we’re learning.’’

Cornerback Phillip Adams was signed to fill Wright’s spot on the roster.

Receiving praise

Sunday’s opponents, the Cowboys, have been less than 100 percent in their receiving corps, most notably Miles Austin (hamstring) and Dez Bryant (thigh).

Austin had 14 receptions for 233 yards and four touchdowns in the first two weeks of the season, but was hurt against the 49ers in Week 2, and only returned to practice this week.

Bryant did not play against San Francisco, but had seven catches for 100 yards and two touchdowns against the Redskins and Lions.

Regardless, the Patriots are expecting an explosive passing game from the Cowboys.

The Patriots’ pass defense is ranked last in the league (326.6 yards per game), but held the Jets to 158 yards last week. With Austin, Bryant, and tight end Jason Witten, the Cowboys present a challenge.

“It’s definitely a tough job,’’ said second-year cornerback Devin McCourty. “Their tight ends are very good in the pass game. Then they have two receivers that are good at getting vertical but also bigger guys that can catch the ball short and break tackles. Probably on the whole, as a group, it’s going to be a very tough challenge.’’

As if he never left

When he was released by the Patriots last month, tight end Dan Gronkowski didn’t go far. Not even three weeks later, he was brought back.

“It definitely feels like I didn’t leave,’’ Gronkowski said. “You just come right back in and you’re part of the team again. I have to remember everything and get ready for Dallas.’’

Passing grade

Tim Tebow was named the Broncos’ starting quarterback this week. His mechanics have been widely criticized, but as someone who caught passes from Tebow at the University of Florida, Patriots tight end Aaron Hernandez knows the Broncos are putting the ball in the hands of a playmaker.

“Tim’s a great player and I loved him in college,’’ Hernandez said. “He’s going to make plays. Hopefully, he can succeed because I feel like he’s going to be a great quarterback.’’

“He’s a winner. You want someone like him in your huddle because he’s going to know everything. People may not like his throwing technique, but he’s a winner and he’s going to find ways to make the plays and get that first down, whether he has to run it or throw it, he’s going to make things happen.’’

Hernandez returned last Sunday from an MCL sprain and wore a brace on his left knee.

“You’re not thinking about it when it’s on,’’ he said. “So, you still have to play football. It may make you a tenth of a second slower, but it’s not that big of a difference, and I can’t use it as an excuse.’’

Julian Benbow can be reached at jbenbow@globe.com. Monique Walker can be reached at mwalker@globe.com. Follow her on Twitter @monwalker.